Accelerated long-term forgetting after amygdalohippocampectomy in temporal lobe epilepsy

POLAT B., Yılmaz N. H., MANTAR N., Cadirci F., Sitrava S., Ozmansur E. N., ...More

Journal of Clinical Neuroscience, vol.72, pp.43-49, 2020 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 72
  • Publication Date: 2020
  • Doi Number: 10.1016/j.jocn.2020.01.038
  • Journal Name: Journal of Clinical Neuroscience
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, EMBASE, MEDLINE
  • Page Numbers: pp.43-49
  • Keywords: Temporal lobe epilepsy, Amygdalohippocampectomy, Accelerated long-term forgetting
  • Istanbul Medipol University Affiliated: Yes


Aim of the study: Temporal lobe epilepsy (TLE) has been associated with the phenomenon of accelerated long-term forgetting (ALF). In this study, we aimed to demonstrate the effect of surgery on the ALF phenomena thus contributing to potential explanation of the causal mechanism. Materials and methods: We evaluated 51 patients with TLE related to hippocampal sclerosis who had amygdalohippocampectomy and had remained seizure-free after surgery. A control group consisted of 24 healthy individuals. All were given a verbal learning test assessing recall after 30 min, 1 week and 6 weeks. Results: In our study, the Left-TLE (L-TLE) group showed a statistically significant reduction in the performance at all assessment intervals from 30 min to 1 week compared to the Right-TLE and control groups regarding verbal learning memory test (VLMT) as well as for logical memory. The forgetting rates in the VLMT from 30 min to 1 week were not statistically significantly different between all 3 groups. The logical memory test results equally showed no statistically significant difference in the forgetting rates for the 3 groups between 30 min and 1 week. Conclusions and clinical implications: These results may support ongoing debates assuming the initial low performance in the memory of L-TLE patients to be directly related with left hippocampal-temporal tissue loss irrespective of epileptic activity. The discovery of the ALF phenomenon explains that standard memory tests are unable to detect memory loss in some patients who are experiencing a significant level of problems with forgetfulness in their daily lives.